This is the adjustable strap with a snap hook on each end that replaced the musette bag strap, and was also used with the G.P. ammo bag. These were adopted in 1944 and were probably all O.D. Mine are unissued, Korean War dated, O. D.

There were no giants in WWII. If you are exceptionally tall or wide, there is no battledress of any kind to fit you except reproductions. Even if you are a normal WWII size, real British BD is extremely scarce. Jackets in normal sizes can be found by diligent searching; trousers are nearly impossible.